KVC Westerlo traces its roots to 1917, when students in the municipality of Westerlo, in Belgium's Antwerp province, founded a side called Sportkring De Bist Westerlo. That early club dissolved within five years, but football in the town was revived in 1931 under the name Bist Sport, which soon became Sportkring Westerlo. A splinter group broke away to form Westerlo Sport, and the two rivals eventually reconciled, merging in 1944 to create V.C. Westerlo — the direct ancestor of today's club. The addition of the prefix Koninklijke (Royal) in 1996 marked another milestone, and the club was formally registered with matricule number 2024.
Westerlo climbed steadily through Belgium's amateur and semi-professional pyramid, finally reaching the top flight in 1997. Their most celebrated era followed almost immediately: the club lifted the Belgian Cup in 2000–01, their only major national honour, and recorded their best-ever league finishes of sixth place in 1999–00, 2003–04 and 2008–09. A relegation in 2012 sent them into the second tier for two seasons, but they bounced back as Second Division champions in 2013–14. History repeated itself a decade later when they won the Second Division title again in 2021–22, returning to the Pro League.
In 2019 the club was acquired by Turkish businessman Oktay Ercan, who framed his ambitions around a project called 'KVC Westerlo 2024' and pledged to keep the club rooted in its community identity. Westerlo play their home matches at Het Kuipje — Dutch for 'The Cockpit' — a compact 8,035-capacity ground that reflects the club's tight-knit, regional character. They remain one of the smaller clubs to hold a Belgian Cup winner's medal.